Fixed systems and methods for extinguishing industrial tank fires, with and without fixed roof, including aerated foam projecting nozzles and center directed nozzles

ABSTRACT

Fixed systems and method for extinguishing large scale industrial tank fires, with and without fixed roofs, and featuring aerated foam projecting nozzles and including fixed center directed nozzles.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a divisional application of, and claimspriority to, parent application U.S. Ser. No. 13/261,640, having thesame inventors, of the same title, and filed Apr. 16, 2013, which parentapplication is a national stage of PCT application PCT/US11/01768 ofsame inventors and title, filed Oct. 17, 2011, which is acontinuation-in-part of, and claims priority upon, four provisionalapplications by the same inventors: U.S. Ser. Nos. 61/455,367,61/461,413, 61/463,296 and 61/519,071 filed Oct. 19, 2010, Jan. 18,2011, Feb. 14, 2011 and May 16, 2011 and entitled “Rapid Tank Response,Equipment and Methodology;” “A Point and Shoot System (including aspreviously filed,) An Ambush System and Method and a Hollow Point Systemand Method, all for Fighting Industrial Tank Hazards;” “FurtherDevelopments—Fixed System (Point and Shoot, Ambush and Hollow Point),”and “Fixed/Semi-Fixed Aerated Foam Systems for Industrial Tank Hazards,”respectively. The four applications are all herein and herebyincorporated by reference in their entirety to the extent permitted bylaw and regulation.

FIELD OF THE INVENTION

The field of invention includes fixed systems for fighting fire inindustrial tanks including a wand with at least one laterally directednozzle projecting aerated foam around interior tank wall portions plus afixed centrally directed nozzle for projecting aerated foam. Theinvention also relates to a fixed system for fighting fire in largeindustrial tanks with a fixed roof.

BACKGROUND OF THE INVENTION Industry Background

Williams Fire and Hazard Control, Inc. (Williams) has been a leader inthe design, development, and production of specialty firefightingequipment and methodology for use on large industrial tank fires. Astudy published in a report by SP Fire Technology in 2004, written byHenry Persson and Anders Lonnermark, stated:

-   -   Despite the lack of large-scale tank fire tests in the last 15        to 20 years, significant improvements have been made regarding        tank fire fighting using mobile equipment. The pioneers in this        development have been Williams Fire & Hazard Control Inc. (WFHC)        drawing attention to the need for solving the logistics during a        fire and to use relevant tactics. By using large capacity        monitors, large diameter hose and foam concentrate stored in        bulk containers, the logistics become manageable. The use of        large-scale monitors has also made it possible to achieve        sufficiently high application rates in order to compensate for        foam losses due to wind and thermal updraft. Williams have also        introduced the “Footprint” technology where all the foam streams        are aimed towards one single landing zone on the fuel surface,        resulting in a very high local application rate making the foam        spread more rapidly and efficiently. One of the main factors in        achieving an efficient extinguishment, according to Williams, is        the use of a high quality foam, suited for tank fire protection        and until recently, they were primarily using 3M AFFF/ATC. Due        to 3M's withdrawal from the foam business a similar foam type is        now used, manufactured by Ansul. “Thunderstorm ATC.” In 1983,        Williams extinguished a 45.7 m (150 ft) diameter gasoline tank        in Chalmette, La. (“Tenneco fire”), which at that time was the        largest tank ever extinguished using mobile equipment. A new        record was set in 2001 when an 82.4 m diameter (270 ft) gasoline        tank was extinguished in Norco, La. (“Orion fire”). The concept        for tank fire fighting used by Williams has been shown to be        successful in many other fires [35] and the concept has also        been successfully used by other companies, e.g. during the        Sunoco fire in Canada 1996.”        (Note: Thunderstorm™ foam concentrates are now developed and        produced by Chemguard Inc.)        Historical Development

Historically, Williams has specialized in mobile equipment andmethodology. “Fixed system” approaches to large tank fires,historically, have demonstrated limited success in the industry as wellas high cost.

On the one hand, for “rim seal fires” (fire around the rim of a tankfloating roof, around the roof seal) traditional fixed system approachesplace a large number of “foam chambers” or “foam pourers” around theperimeter of the storage tank, every 40 feet or every 80 feet dependingupon whether the “foam dam” on the floating roof is 12″ or 24″ high.These devices drop or “pour” highly aerated fire fighting foam down thetank wall into the tank “periphery,” or area between the tank wall andthe “foam dam” on the floating roof, by force of gravity. The cost forsuch system is high.

On the other hand, for “full surface liquid tank fires” in 100 foot plusdiameter tanks, proven fixed systems have not existed. That is, to theinventor's best knowledge, no fixed system has put out a fully engagedfull surface liquid tank fire in a 100 foot plus diameter tank.

Williams Fully Portable Systems

“Rim Seal Fire”

Before the “Daspit Tool,” Williams successfully used fully portabledevices and methods to extinguish “rim seal fires,” using a two partattack. In the first phase of the Williams attack a fire fighterapproached the tank and hung a portable device (foam wand with anon-reactive nozzle design) over the top edge of the tank proximate aplatform or landing. The wand largely dispensed foam directly under thedevice, suppressing the fire in the immediate vicinity, over a 30 to 40foot length. After a “beachhead” was established, a “beachhead” of 30 to40 feet of tank rim with no flames under a landing, fire fightersmounted the tank wall using the ladder leading to the landing, andcarried up handheld nozzles and hoses. (The gpm's of handheld nozzlesare roughly limited to 60 gpm for a one person nozzle and a 125 gpm fora two person nozzle.) These nozzles were the primary fire extinguishingtools for the seal fire. Having gained access to the top of the tankwall through use of a foam wand, the fire fighters extinguished the“seal fire” by walking the “wind girder” around the tank wall, using theportable nozzles in a known manner.

Daspit Tool System

Subsequently, Williams developed a Daspit tool, a portable base foraffixing a portable nozzle and monitor to the top of a tank rim or wall.With the Daspit tool, nozzles up to 2000 gpm could be attached to thetop of a tank wall. Specifically again, on “a rim seal fire,” with thisimproved technique, a portable foam wand device was again used todispense foam downward to establish a “beachhead” area. A fire fighterthen carried a Daspit Tool™, (being a clamping device used to secure atemporary fire fighting monitor and nozzle to the top edge of a storagetank, or any other approved mounting location) and hose while climbingthe ladder and attached the Tool to the tank rim above the beachhead.The monitor and nozzle were then pressurized with water/foam solutionand directed by the fire fighter stationed at the landing to dispensefoam inside the tank and shoot out fire located around the tank'sperimeter. The entire attack could be set up and executed in a matter ofminutes, after, of course, the responding fire fighters had arrived atthe scene.

Full Surface Fire

In September of 2004 Williams was called to Cushing, Oklahoma to assistin the extinguishment of a “full surface” 117 foot diameter crude tankfire. The Williams team arrived with portable foam wands and with“Daspit Tools,” monitors and nozzles. (Again, “Daspit Tools” permitstaging a monitor and nozzle on a tank wall rim. The “Daspit Tool”provides a base for a monitor and nozzle.) Williams first used portablefoam wands to extinguish the fire around an area under a platform andladder along the wall of the tank. Having gained “control” of thatlimited area, Williams personnel mounted the ladder of the burning tankto the platform, secured a Daspit Tool there and directed its monitorand nozzle to extinguish the full surface crude tank fire. Thus,Williams provided evidence that a portable foam wand and sufficientlylarge portable monitor and nozzle (rendered useable by virtue of theDaspit Tool base) could be effectively used to extinguish a “fullsurface tank fire”, at least of crude in at least a 117 foot diametertank.

Williams Fixed Systems Development

Williams had long appreciated that a “fixed” system, performingappropriate tasks, would be faster and offer much lower risk of harm anddanger to personnel. (Danger to personnel includes the clutter on aladder provided by the hoses necessary to supply a portable monitor anda wand. Furthermore, if such hose were to break while it runs up theladder, the personnel involved with the ladder and platform would be putin significant danger.)

A problem to solve, and a goal for Williams in industrial tank firefighting, became to develop a cost-effective, reliable, fixed system forquickly and efficiently blanketing appropriate areas of a tank fire withfoam, including not only the “periphery,” (which is the location of the“rim seal fire,”) but also a tank “full surface fire.” Such system,moreover, should perform satisfactorily for tanks of 200 and 300 and 400feet diameter, and even greater, and include tanks with and/or without afixed roof, and should not be prohibitively expensive.

The resulting Williams commercial embodiments, discussed below, weredeveloped, tested and designed to solve these problems and meet thesegoals. The commercial embodiments were designed to protect: (1) floatingroof only tanks against “rim seal fire” and vapor hazard; (2) floatingroof only tanks against “rim seal fire” and full surface fire; and (3)fixed roof tanks against any surface hazard. The inventive systems arecost-effective and practical, for tank diameters from 100 feet to above400 feet.

The instant inventors have demonstrated, in the development process,that the industry erred in certain prior assumptions regarding theproper expansion of foam needed for fixed systems, and regarding thecapacity to throw or project and run an adequately expanded foam.

The instant inventors have demonstrated, with side by side testing, that“projecting” and “directionally discharging” an “aerated foam” (anexpansion of between 2-to-1 and 8-to-1) from an aerated foam nozzle canproduce a focused stream of at least 1100 gpm of aerated foam, with asignificantly enhanced tight landing footprint, and with a surprisingfoam run, and including a surprising foam run speed and fire fightingeffectiveness. The inventors have shown, with testing, that theiraerated foam nozzles can reach a more extensive tank fire surface in ashorter period of time than can prior art “foam chambers.” The novelsystem can extinguish larger tanks with fewer units and is applicablenot only to rim seal fires but also to full surface liquid tank fires,including of those of large tanks. The instant inventions, supported bytest results, promise cost effective fixed systems to extinguish firesin tanks of diameters greater than 200 feet, greater than 300 feet, andgreater than 400 feet. The instant fixed systems are designed to beattached along the tank outer wall, and to discharge into the tank froma point near a top tank wall portion, thereby enhancing the reliabilityas well as the cost effectiveness of the fixed system, in the event of ahazard.

Invention Development Stages

The instant invention proceeded in several stages. A first determinationwas made, based on experience and testing, to actively pursue outer tankwall mounted units discharging proximate the tank wall upper rim. (Theinventors have experimented with “bubble-up” or so-called Type I systemsbut have not yet been able to successfully test a satisfactory,practical and cost effective bubble-up system. Pipe-inside-the-tanksystems, based on extensive experience, were deemed impractical giventhe prevalence of floating roofs and the complications inherent therein.In regard to roof mounted systems, either fixed roof or floating roof orsystems that “extend-over” the top of the liquid, experience againindicated far too high a likelihood that such a fixed system would beplaced out of service by the very incident that causes the fire orhazard.)

A second determination, based on testing, was to preferably dischargeaerated foam from an aeration chamber proximate to and upstream of thenozzle, the aerated foam preferably having at least a 2-to-1 to 8-to-1expansion ratio. A 3-to-1 to 5-to-1 ratio was preferred. A tubular jetambient air aeration chamber provided a reliable structure for theaeration, able to perform while enduring heat and stress. It wasdetermined by testing that this aerated foam could be significantlyprojected, could produce a significant foam run, and could run quicklywithout losing fire fighting effectiveness.

Thirdly, the inventors created a nozzle that could significantly,directionally, “project” and/or “forcefully project” a proper aeratedfoam in a “substantially focused stream,” to land in a focused pattern,with an enhanced tight landing footprint, and again with significantfoam run and effective fire extinguishment characteristics. A key tothis stage was a stream shaper.

One general belief in the industry had been that “forcefully projecting”aerated foam destroyed the bubbles and resulted in poor foam quality andpoor foam run. Prior art fixed systems with aerated foam chambers didnot “forcefully project” aerated foam. Rather, for rim seal fires and/orsmall tanks, they poured or dropped by gravity highly aspirated foamdown the inside walls of the tank. This resulted in a low gpm ofdischarge and a poor foam run.

The instant inventors demonstrated that, with the instant nozzles, theexpectation of poor bubble quality and poor foam run for “projected” or“forcefully projected” aerated foam was misplaced. Use of a streamshaper may be instrumental in helping to secure the good results andenhanced landing footprint.

Testing has shown that a stream shaper can significantly enhance theintegrity and focus of thrown footprints of aerated foam. Aerated foamdischarged through a proper stream shaper has non-destructively landedat least dozens of feet away, in tightly focused footprints, and runsurprisingly further and quicker than industry predictions, whilemaintaining the fire fighting effectiveness of the bubbles. A 2-to-1 to8-to-1 expanded foam, preferably a 3-to-1 to 5-to-1 expanded foam, canbe non-destructively landed in tight target areas to a greater extentand further away than industry expectations. The stream shaper is onekey why the instant system can land foam at least 20 feet away in a tank“periphery” and run the foam greater than 100 feet further in theperiphery. In preferred embodiments a footprint-enhancing stream shaperfor an aerated foam nozzle has four or greater fins, each fin having alongitudinal dimension greater than a radial dimension. Preferably eachfin has a longitudinal dimension greater than twice its radialdimension. Preferably also the stream shaper fins are installed in a tipof a nozzle such that the downstream end of the fins is approximatelyflush with the nozzle tip discharge orifice.

Terms

The following use of terms is helpful in discussing the structure andperformance of the instant inventions as they developed.

The term “riser” is used to refer to any pipe or line or system of such,affixed to or near or adjacent to an outer tank wall, installed toprovide water, water and foam concentrate and/or fire fighting fluid toa top portion of a large industrial storage tank. Although risers areshown herein as vertical pipes, they could be any shape, and inparticular, they could be a combination of vertical and/or circularportions. E.g. one or more fluid distribution rings could be installedaround a tank, connecting with vertical riser portions. A riser can comein sections, as illustrated herein.

A “tip” of a nozzle is a nozzle barrel portion terminating in adischarge orifice, frequently including a swedge-down portion to enhancedischarge pressure.

A “fin” (also referred to in the art as a vane) directs fluid flow in aconduit.

A “stream shaper” provides fins or vanes extending in a nozzle orconduit. A fin radial dimension is the dimension measured radially froma center axis of a barrel or conduit out toward the barrel or conduitwall. A fin longitudinal dimension is the dimension of the fin measuredlongitudinally in a nozzle or conduit, along a nozzle or conduitlongitudinal axis or in the upstream/downstream direction of flow.

A “deflector,” as used herein, provides an obstruction in a fluidconduit, directing a portion of fluid flowing therein toward a dischargeorifice or port.

A tank “periphery” is an annular area on an top of a floating tank roof,between the tank wall and the floating roof “foam dam.” Foam dams areusually 24 inches high or 12 inches high. A “rim seal fire” is a fire inthe “periphery.” (A full surface fire can ensue when a floating rooffails, e.g. sinks or tilts.)

An “aerated foam nozzle” or an “aerated foam projecting nozzle” will beused to indicate a nozzle that discharges foam created from a foamingconcentrate that has passed through an ambient air aeration chamberlocated at, proximate to, and/or just prior to, a nozzle.

Two nozzles discharging “in roughly opposing directions” will be used tomean discharging in roughly opposite directions, within at least +/−15°of a median “directly opposite” directional axis. By one measure, thus,the included angle between two discharge axes of two nozzles dischargingin roughly opposing directions, taken in the direction of discharge,will be between 180° and 150°.

A “substantially focused” stream indicates a discharge of foam where atleast 60% of the foam remains within a 20 degree cone around a dischargeaxis during flight.

A “projecting” nozzle means a nozzle that, if set at 0° inclination tothe horizon and at a supply pressure of 100 psi, and if a landingfootprint is measured on a horizontal plane five feet below thedischarge orifice, and when throwing aerated foam with an expansion ofbetween 3/1 and 5/1, then the nozzle can land at least 50% of theaerated foam greater than 5 feet from the discharge orifice and can landsome foam greater than 20 feet. “Projecting” thus means landing at least50% of foam, aerated with an expansion of between 3-to-1 to 5-to-1,greater than 5 feet from the nozzle discharge orifice and landingsignificant foam greater than 20 feet, if discharged horizontally andmeasured on a plane five feet below the discharge orifice.

A “forcefully projecting” nozzle means a nozzle that, if set at 0°inclination to the horizon and at a supply pressure of 100 psi, and if alanding footprint is measured on a horizontal plane five feet below thedischarge orifice, and when throwing aerated foam with an expansion ofbetween 3/1 and 5/1, then the nozzle can land at least 50% of theaerated foam greater than 50 feet from the discharge orifice and canland some foam greater than 80 feet. “Forcefully projecting” thus meanslanding at least 50% of foam, aerated with an expansion of between3-to-1 to 5-to-1, greater than 50 feet from the discharge orifice andlanding some foam greater than 80 feet, if discharged horizontally andwith a landing footprint measured on a horizontal plane 5 feet below thedischarge orifice.

The concepts of “substantially focused” stream and “projecting” and“forcefully projecting” together with “aerated foam nozzle” helpdistinguish the instant inventive nozzle and wand systems from aspiratedfoam discharge devices of the prior art. Prior art discharges fromtraditional “foam chambers” or “foam pourers” are not “substantiallyfocused” or “projecting.” On the other hand, the term “aerated foamnozzle” distinguishes the instant nozzles from master stream nozzles ofthe prior art, for instance, nozzles that throw a water/foam concentrateliquid mixture where essentially all aeration takes place significantlyafter leaving the nozzle structure rather than in an associated upstreamor in-nozzle aeration chamber.

Given the surprisingly good foam run results with the instant nozzledesign and aerated foam, the inventors tested “opposing nozzle” fixedunits, referred to by the inventors as “wand heads” and “wands.” “Twonozzle” and “three nozzle” fixed units, or “wand heads” or “wands,” weretested, discharging roughly horizontally and primarily left and/orright, and optionally, “toward the center.” For insertion throughexisting openings in a wall of a “fixed roof” tank, a conduit with asingle center pointing nozzle plus dual non-obtrusive side ports withinterior deflectors was tested, the unit suitable for inserting intoexisting fixed roof tank wall flanged openings.

The “wand heads” are adapted to be supplied by “risers,” mounted on,proximate to or about outside tank wall portions, the “wand heads” to besecured so as to discharge just inside a top tank wall portion, forenhanced reliability. The “wand heads” preferably include a proximallylocated ambient air aeration chamber providing properly aerated foam forthe nozzle(s). The aeration chambers are served by water/foamconcentrate line(s) or pipe(s), again typically referred to as “risers.”A fixed wand head with two opposing nozzles preferably directsdischarges roughly left and right, projecting aerated foam substantiallyhorizontally and in roughly opposing directions. A fixed separate riserand fitting can be provided, especially proximate a tank ladder andlanding platform, to supply and support an additional fixed nozzle orportable monitor and nozzle, which can project foam toward the center ofthe tank or otherwise around the tank. Preferably a “three nozzle” fixedunit for open floating roof tanks can be installed to discharge left,right and roughly toward the center. For fixed roof tanks, a singlecenter pointing nozzle with two conduit-located deflection ports can beinstalled, the ports functioning as side nozzles. The unit can beinserted through flanged openings typically provided in existing fixedroof tanks. The single conduit nozzle plus two “deflector ports” candischarge left, right and toward the center of a tank with a fixed roof.

(The inventors further teach, for alcohol or the like liquids, possiblynot discharging both left and right but alternately discharging all leftor all right, to establish a swirl pattern run, and to further bank thedischarge against the wall to minimize plunge.)

(Preferably in most embodiments a fourth smaller orifice will dischargea relatively small amount of aerated foam, say less than 150 gpm,directly down the tank wall to land and cover tank surface directlyunder the unit. Frequently this small fourth discharge port may not bementioned herein, and in many cases it appears unnecessary. However, itwill likely be included in commercial units out of caution.)

The instant system thus offers a cost effective solution to a costly anddangerous problem. Providing first responding fire fighters with aproper means for successful extinguishment of at least tank rim sealfires, and preferably also means for full surface vapor suppression andmeans for extinguishing full surface liquid tank fires, by strategicallyand permanently fixing a relatively few inexpensive components onto atank, as well as providing supporting tools (monitors, nozzles, hose,and pumps,) should be paramount in considering how to best protect ahazard. Doing so ensures a good relationship with the first respondersas well as provides a better solution to large tank hazards.

To recap and reflect on the development history, a Williams two stage“fully portable” attack for “rim seal fires,” and even for “full surfaceliquid tank fires,” has been successful. However, as required by the twostage “fully portable” attack, requiring humans to carry hoses up a tankladder to the tank landing, and to charge the hoses around their feet inorder to activate a primary system, presented a personnel risk that wasnot attractive. Unmanned or largely unmanned fixed systems presented afar more attractive personnel environment. However, any fixed orsemi-fixed system must also approach the degree of reliability andflexibility and cost effectiveness as that provided by the two stage“portable” system.

A surprising discovery, that heightened the reliability, costeffectiveness and flexibility of the instant fixed systems, came withthe testing of a landing footprint-enhanced, “aerated” foam nozzle“projecting” aerated foam. The aerated foam nozzle, with tight landingfootprint-enhancement, tested to show that it could “throw” aerated foamsignificantly left and/or right while still landing a predominantportion of that foam in the narrow tank “periphery.” Further, the nozzlecould throw or project aerated foam successfully for a significantdistance, e.g. at least 20 feet, while landing the foam predominately inthe periphery. And the momentum of the “throwing” or the projectingenabled the system to “run” foam, tests showed, a surprising distance,120 feet both left and right of the nozzle, and to do so very quickly.As a result, a footprint-enhanced aerated foam nozzle could form asuitable cost effective primary fixed means for at least extinguishingrim seal fires. To compare with the Williams prior “portable system,”the prior portable foam wand was only used to establish a “beachhead”directly below the wand, which allowed humans to mount the tank wall atthe wand position by the ladder and to put into place the primary fireextinguishing system, fed by hoses running up the ladder. To thecontrary, with the instant novel fixed systems, a portable monitor andnozzle, if used, becomes secondary. A “fixed left and/or right wand”becomes the key element of the primary fire extinguishing system for the“rim seal fire.” A further fixed center pointing nozzle covers a fullsurface fire.

Discussion of Other Discovered Teachings

The problem of an effective practical reliable design for a fixed fireextinguishing system for tank fires, especially in tanks of diameter ofgreater than 100 feet and 200 feet, has existed for a long time. Searchinto existing solutions uncovered the following.

Foam Chambers—for Example, Blomquist U.S. Pat. No. 3,876,010

For floating roof seal fires, “foam chambers” or “foam pourers,”discussed above; dropping highly aspirated foam between a tank wall anda floater roof “foam dam” have been a traditional fixed fire fightingsystem solution. These systems are inadequate to attack a “full surface”fire in a >200 foot diameter tank and likely inadequate for > a 100 footdiameter tank. Their foam run is typically less than 50 feet, so that alarge number of such chambers are required. Given the degree ofexpansion imparted to the foam, the foam run is slow and short and thegpm is limited. Applicant experimented with the common foam chambers toconfirm that the run of their highly aspirated foam was only about 40-50feet in each direction around the tank perimeter or periphery (e.g. inthe area between tank wall and the “foam dam” on the floating roof.) Andthis 40-50 foot run was also relatively slow.

Saval and Knowsley

A “Saval” apparatus was noticed on the Internet and a similar Knowsleyapparatus discovered. This apparatus type proposes two 45° down pointingnozzles, “discharging” left and right, stationed along the wall rim, (aswell as a small directly downward discharge). The two 45° nozzles do notdischarge “significantly horizontally” and no nozzle is proposed todischarge “toward the center” of the tank. Further Saval's nozzlesappear to “bank” their discharges against the tank wall. The effect ofbanking could be to soften the impact of landing on the liquid and/or todirect more of the foam into the periphery and/or to heighten theaeration. However, one of skill in the art knows that the “banking”technique lessens the lateral force behind the foam, wastes projectionenergy and reduces foam run capability. Neither Saval nor Knowsley claima novel or exceptional “foam run” capability. This implies that Saval'sand Knowsley's foam run is in the same order as that of the traditional“foam chambers” and/or “foam pourers.”

Uribe US Patent Publication No. US 2004/0140106

Uribe teaches a tank wall mounted fixed system nozzle with an aerationchamber. The degree of aeration is not mentioned. No stream shaper isdisclosed. Uribe does not discharge right or left, but only toward thecenter, as with the Nihilator below. Uribe asserts that eventually hisdischarged foam will cover a whole tank surface. Since one of ordinaryskill in the art knows that foam has a limited lifetime and a limitedrun, Uribe's statement implies that Uribe's tank is inherently of lessdiameter than 100 feet.

Nihilator

Reference to a Nihilator device was located, although the Nihilatorappears to be no longer offered as a commercial product. One of ordinaryskill might surmise that the Nihilator was not effective. The Nihilatoris a center pointing nozzle apparently designed for a fixed roof tankand has an aeration chamber. The Nihilator discharges foam toward thecenter of the tank and suggests that it be used with traditional foamchambers.

Major Commercial Embodiments

The instant invention and its related embodiments have several majorcommercial embodiments. For ease of reference, the current majorcommercial embodiments are given graphic names.

Primary Target—Floating Roof but No Fixed Roof—Large Tanks

-   -   “Point and Shoot” (semi-fixed) System—Useful for:        -   Rim seal protection and fire fighting        -   Full surface foam blanket when no fire exists, e.g. for            sunken roof vapor suppression

Advantages

-   -   Each wand can protect up to 240′ of seal rim circumference, as        opposed to 40′ or 80′ with conventional foam chambers; therefore        fewer wands are needed    -   Portable monitor and nozzle provides back-up redundancy and        vapor suppression capability    -   Low costs, minimal installation    -   “Ambush” (fixed) System—Useful For:        -   Full surface protection, rim seal fire and fully engaged            full surface liquid tank fire (floating roof sunk)        -   Number of systems per tank depends on tank diameter (and            product stored)        -   System can be used to extinguish rim seal rim fires with            center nozzle valved off so as not to overload a floating            roof

Advantages

-   -   Left/right/center (and possibly down-the-wall) streams can        discharge and/or project aerated foam in 3 or 4 directions    -   System capable of discharging 1900 gpm from each assembly on the        largest model    -   Each wand can protect up to 240′ of seal rim and up to 150′        toward the center    -   Requires significantly fewer wand installations than prior art

Primary Target—Fixed Roof, Large Tank

-   -   “Hollow Point” (fixed) System—Useful for:        -   Closed roof, full tank protection

Advantages

-   -   Easy installation on existing tanks, through existing single 6″        flanged holes.    -   Each wand can protect up to 240′ of seal rim and up to 250′        toward the center    -   Incorporates a Teflon vapor seal to stop vapors from traveling        down the tube and out aeration holes    -   Can project 2700 gpm of foam total, via forward and left/right        and down streams    -   Requires significantly fewer wand installations than prior art

Again, success of the above embodiments may be based in part upon thedevelopment of a stream shaper affixed in the tip of the nozzles, whichfacilitates providing a projecting and forcefully projecting foamnozzle, as well as developing a properly aerated foam for the context.

The Major Commercial Systems and Methodologies—in Greater Detail

The invention, as introduced and discussed above, relates to variousaspects and embodiments for fixed and semi-fixed systems and methods forextinguishing liquid tank fires in large industrial storage tanks. Theinvention covers tanks with and without fixed roofs and systems that arefixed or semi-fixed, and systems developed primarily for rim seal firesand for full surface liquid tank fires.

The Semi-Fixed System (for Rim Seal Fire and Vapor Protection)—Point andShoot, Summarized

The Point and Shoot fixed wand and riser system is a semi-fixed systemthat can be used immediately for “rim seal fire” protection as well asfor vapor suppression. The Point and Shoot fixed wand and riser systemis predicated upon the successful rim-seal extinguishments made byWilliams using fully portable equipment, as well as the subsequentDaspit Tool development. Given the further development of a properaeration chamber and a stream shaped nozzle combination, aerated foamnozzle units, or “wands,” fixed to the wall of the tank become acost-effective primary “rim seal fire” extinguishing means. A furtherfixed riser, for supplying fire fighting fluid to a portable monitor andnozzle, can provide redundancy in case of damage to the primary systemas well as extra full surface vapor suppression capability. (And ofcourse, further independent fixed risers with fixed center pointingnozzles offer a fully fixed full surface fire protection capability.)

Thus, the semi-fixed Point and Shoot wand and riser system and methodprovides safer and quicker extinguishment for rim seal fires, as well asa back-up for component disablement or vapor suppression. This minimalfixed wand and riser system requires only strategically permanentlyaffixing a few inexpensive components directly onto a tank. As aconsequence of a proper combination of a footprint-enhanced nozzle witha properly aerated foam, the left and right nozzles of a wand can befixed 220 to 240 feet apart, (as opposed to 40 to 80 feet apart withprior art foam chamber systems.) Thus, the footprint enhanced aeratedfoam nozzle wand system can be staged as a primary fire extinguishingsystem for the “rim seal fire” while one or more risers, installedproximate a tank landing and ladder for the quick attachment of portablemonitor/nozzles, can be regarded as redundant backup rim seal fireprotection, in case of damage to the primary system, and as a capabilityto provide full surface vapor suppression if a floating roof partiallyor totally sinks. This semi-fixed system permits attacking a seal firequickly with much less risk to personnel.

The semi-fixed elementary system, called the Point and Shoot System, hasa recommended layout as follows:

Number of Foam Wands for Full Encirclement Seal Protection 240′ CoverageFrom Each - 24″ Tall Foam Dam Required at least 220′ coverage fromeach - 12″ tall foam dam Tank Diameter No. of Foam Wands Required 0′-76′ 1  77′-153′ 2 154′-229′ 3 230′-306′ 4 307′-382′ 5 383′-458′ 6Williams Fire and Hazard Control 1-800-231-4613 Note: The number ofprior art “foam chambers” which would be required to protect the abovetank sizes is many multiples of the number of the instant novel “foamwands” required, due to the extended coverage of the instant “foamwands” (240′ vs. 80′ or 220′ vs. 80′).

The Point and Shoot semi-fixed system is particularly applicable forlarge tanks with no fixed roof for “rim seal fires” and full surfacevapor suppression. A major advantage is low cost. The Point and Shootsystem is characterized by a pair of aerated foam projecting nozzlesattached together in a fixed “wand,” structured to discharge in roughlyopposing directions and roughly horizontally. The aerated foam tank wandhas been demonstrated to be able to land and run foam approximately 120feet in each direction in the tank “periphery,” that is the spacebetween the “foam dam” and the tank wall of a floating roof. See belowtest results. Preferably in addition to the fixed foam wands risersattached to or about the tank wall, at least one additional at leastfour inch riser is attached to the tank wall to be associated with thetank landing ladder system. The additional riser is structured tocommunicate fire fighting fluid from approximately the ground toapproximately the top of the tank and is structured with a fitting atits end, proximate the top of the tank, the fitting suitable forattaching a portable (at least 150 gpm at 100 psi) monitor and nozzle.

The Fixed System for Floating, not Fixed, Roof—Including Full SurfaceFire—Ambush Summarized

One new primary danger arises from the fact that industrial storagetanks for storing flammable liquids and hydrocarbon products are beingconstructed of ever greater diameters. Today 405′ diameter tanks, andgreater, are being constructed. Large scale portable fire fightingnozzles, such as 10,000 gpm, 12,000 gpm or 14,000 gpm nozzles, capableof throwing fire extinguishing and hazard suppressing liquids (water andfoam concentrate) over the top of the tank wall typically recite maximumranges in the 400-500 foot range. Fire fighting foams from the largescale portable nozzles can be relied on to run, at best, approximately100′. (Conservatively, the foam might only be reliably counted upon torun about 80 feet.) Thus, portable fire fighting nozzles effectivelyaddressing a full surface, fully engaged flammable liquid tank fire in a405′ diameter tank by throwing foam over the wall from an upwindlocation probably have to be staged within 100′ of a tank wall.Considerations of logistics as well as the existence of moats, buildingsand other equipment and piping around the tanks, and especiallyconsiderations of heat and personnel safety, render extremelyproblematical any tactic requiring approaching a fully engaged fullsurface liquid tank fire in a 405′ diameter tank closer than 100′.

Further pressure for improvement comes from the fact that the value, tothe tank owner, of a gallon of the product in the tank is alsoincreasing dramatically. Owners of large tanks and of large tankproducts want the product and the tank to be protected from fire.

The above considerations incentivized the inventors to develop a fullyfixed system, including one or more fixed center pointing nozzles plusan aerated foam wand, preferably a left and right discharging wand butpossibly an all left or all right discharging wand. The system is knownas the Ambush and provides a first defense for addressing fire and vaporhazards, including full surface liquid tank fires, in all tanks withouta fixed roof, but especially in large diameter tanks.

The Ambush could be implemented in one fashion as a “fixed” Point andShoot System. The Point and Shoot riser provided with a fitting forattaching a portable monitor and nozzle, located near the tank ladderand landing, could be provided instead with a permanently fixed centerpointing nozzle, such as a master stream self-educting nozzle. The riserand nozzle could look and function much like the Hollow Point riser andnozzle, without however the lateral space constraints, the side portsand without the necessity of an aeration chamber. The adjustment of thenozzle could be fixed or set with respect to the tank size and otherfixed wands such that the nozzle covers a relevant center portion of thetank surface with foam. No separate ambient air aeration chamber wouldbe required, as known in the master stream fire fighting nozzle field. Aseparate fixed riser and nozzle need not be limited to being locatednear a tank ladder and landing. Only so many fixed center directed riserand nozzles need be included as will adequately cover the center portionof the tank surface with foam, in context.

An Ambush System provides a tailored design of three nozzle units, orwands, preferably with all nozzles using one or two proximate ambientair aeration chambers and all working off of one or two associatedrisers. These three nozzle units are designed to be installed as unitsaround a tank.

The three nozzle, fixed, aerated foam wand system includes a set offixed aerated foam nozzles. This set of nozzles, each referred to as afixed “wand,” has left and/or right and over the top (toward the center)capability, all with enhanced landing footprints. Preferably the unitsof three nozzle wands are spaced around, and proximate to, the innertank wall, each unit preferably providing two nozzles that dischargepredominantly left and right, along inner tank wall portions, and athird nozzle that discharges toward the center. Preferably the “towardthe center” nozzle discharges at least beyond an approximate 80′ annularring of foam, anticipated to be created upon an open tank surface by theleft and right discharging nozzles. (In some cases the three nozzle wandunit also provides a fourth small port or nozzle to discharge directlybeneath the wand and on the inside of the tank wall.) Any disablement ofa fixed wand due to a particular fire or hazard or incident can besupplemented by large portable nozzles staged on the ground, throwingfoam over the tank wall, as is known in the art.

The perimeter of a 405′ tank runs approximately 1,250 feet. Testingshows that the instant novel fixed foam wands (Ambush System) should beable to direct foam to run at least 80′ to 90′ in each direction,preferably 120 feet, and to also run the foam 80′ or so inward towardthe center of the tank. (Again, in addition, a small amount of foam maybe discharged directly below the fixed foam wands.) These nozzles couldcover the inner tank wall with a roughly 80′ wide annular foam ring,relatively quickly. A third nozzle attached to each fixed wand,preferably with its own aeration chamber, projects foam toward thecenter of the tank and at least toward the inside of the 80′ annularfoam ring being established. Preferably, for a large tank, the thirdnozzle lands a footprint of foam with a footprint midpoint approximately90 to 120 feet radially inward of the tank wall. The length of thelanding footprint should preferably extend at least 20 to 30 feetforward and backward from the landing midpoint, along the dischargeprojection line. The landing footprint should preferably spread at least15 to 20 feet laterally from the discharge projection line. Such adischarge of foam has been shown to be capable of running foam towardand through the center of a 405′ diameter tank. Taking the centerprojected foam together with the peripherally discharged foam, a totalgpm of foam should be selected such that the surface of the tank wouldbe covered with an adequately deep and lasting foam blanket. That is,the gpm of the wands and nozzles should take into account the desiredand/or required application rate density for the tank surface.

This fixed three nozzle open system and methodology has an advantage ofconcentrating a foam blanket on portions of the tank liquid surfaceadjacent to the tank walls. The portions adjacent to the tank walls areimportant because the tank wall itself can retain significant heat. Thetank wall typically needs the most cooling. For a 405 foot diametertank, for instance, seven or eight large three nozzle fixed foam wandsmight be utilized, each large three nozzle foam wand dischargingapproximately 2,000 gpm of water/foam concentrate total from its nozzlecluster. In a preferred embodiment a nozzle discharging to the left andto the right might discharge approximately 700 gpm each. A nozzledirected toward the center might project approximately 500-900 gpmtoward the center. A small port discharging immediately under the fixedwand might discharge approximately 100 gpm downward.

Again, to the extent that one or more fixed foam three nozzle wands aredisabled by the fire or an explosion, large portable fire fightingnozzles can be staged on the ground and used to supplement thenon-disabled portions of the fixed system.

In the three nozzle fixed aerated foam wand system the dischargeorifices for the nozzles preferably contain fins, or stream shapers, tominimize the turbulence in the discharge of aerated foam out of thenozzles. Minimizing turbulence enhances the range and the run of thefoam, and tightens the landing footprint.

One preferred three nozzle fixed aerated foam wand embodiment includestwo aeration chambers. The aeration chamber(s) typically consist oftubular jets inserted inside of piping proximate a series of air intakeports, and the chamber is situated proximately upstream of the nozzledischarges. The jets, in a known manner, create a low pressure zone,sucking air in through the ports and mixing the water/foam concentratewith air to create an aerated foam for discharge. Bends incorporated inthe conduit between an aeration chamber and a discharging nozzle mayenhance the aeration of the foam. No bend may be included between anaeration chamber and a center projecting nozzle, however, to minimallyaerate that foam in order to enhance foam throw and run. Discharge fromthat nozzle has a longer flight time in which to further aerate. Twoaeration chambers enable tailoring the aeration more closely to thenozzle purpose.

Although the three nozzle system was initially designed to address theproblem of a very large, fully engaged, full surface liquid tank fire(no fixed roof), such as a fire in an industrial tank having a diameterof 405 feet, the fixed three nozzles aerated foam wand system wasquickly seen to have application to tanks of all diameter sizes, and inthe situation of either a fully engaged fire or a rim seal fire orsimply a need for vapor suppression. The large fixed wand is useful evenif a floater remains in place and there is only a seal fire or a needfor vapor suppression over the floater. A valve can be provided toeliminate foam discharged toward the center in the case of a rim sealfire.

Fixed Roof Fixed Nozzle System—Hollow Point Summarized

A fixed roof fixed nozzle wand system has been designed as a directresponse to the issues faced by foam chambers when installed on a closedroof tank for the purpose of full surface protection. One wand of theinstant fixed roof fixed nozzle system projects foam directly toward thecenter of the tank as well as left and right to protect near the innertank walls. The wand unit preferably incorporates a Teflon vapor seal toprevent tank vapors from escaping the tank via the aeration holes in thewand system's supply piping.

In contrast with foam chambers that simply pour foam onto the surfacefrom the circumference of a tank, such that the foam must run across theliquid surface using only gravity as its means of propulsion via thestatic head from the piled up foam near the tank wall, the instant fixedroof aerated foam wand discharge head projects foam out into the tankwith significant velocity, to push the foam toward the center of thetank. From the same wand foam from interior left/right discharge portsis projected to protect the area near the tank walls.

As foam accumulates in the center, it will begin to flow outwards backtoward the tank walls. The foam at the tank walls will meet and flowtoward the center of the tank, closing the gap between the two.

Each fixed roof wand discharge head is preferably designed to flow 1000gpm; 600 gpm is delivered through the center stream projecting towardthe center of the tank with 200 gpm projecting left and right againstthe tank wall. This flow rate can be regulated by an internal jet justupstream of the aeration holes. Air is introduced to the stream at theaeration holes by the Venturi effect created by the internal jet. Thisaerates the foam before it leaves the wand to allow for aerated foam toland on the liquid surface. The ambient air aeration chamber ispreferably intended to create a relatively low expansion foam comparedto other devices, in order to maintain small bubble foam. This foam isbest suited for quickly and effectively running across a liquid surface,thus providing a quick coverage and extinguishment of the tank. One mainobjective of the fixed roof wand system is to improve upon currentmethods of closed roof storage tank protection. The fixed roof wandsystem does so by projecting foam, rather than pouring foam, and bycarefully engineered discharge tip sizes and designs coupled with anefficient ambient air aerator and favorable flow rates, stream shapersand stream straighteners.

One fixed roof wand system recommended layout, for example, is asfollow:

Number of Hollow Point Systems Required for Full Surface Protection 1000gpm Discharge from Each System Tank Diameter Discharge Heads Required 0′-103′ 1 104′-146′ 2 147′-178′ 3 179′-206′ 4 207′-221′ 5 222′-242′ 6242′-262′ 7 263′-280′ 8 281′-297′ 9 298′-313′ 10 314′-316′ 11 317′-330′12 Williams Fire and Hazard Control 1-800-231-4613 Note: The applicationdensities used in the above calculations are based upon an escalatingscale from .12 gpm/ft{circumflex over ( )}2 to .14 gpm/ft{circumflexover ( )}2. These numbers are based upon Williams experience withextinguishing large full surface storage tank fires.Special Methodology—Alcohols

Alcohols and related liquids and polar solvents are known to attractwater out of foam bubbles. Foam, therefore, is preferably landed“lightly” on alcohols or like fluids to minimize the depth of any plungeof the foam below the liquid surface. The inventors teach that a swirlpattern may be preferable for running foam landing on alcohol or thelike liquids in the case of fire. Thus the inventors teach, for tanks ofalcohol or related liquids or polar solvents, a method of bankingdischarged foam against inner tank walls prior to landing the foam onthe liquid, and discharging the foam predominantly all left or allright, from a plurality of nozzles, to develop a swirl pattern run forthe foam in the tank.

Aerated Foam

The preferred foam for producing the requisite aerated foam for theinstant fixed systems is to use an ambient air aeration chamber locatedjust upstream of the nozzles. It is known in the art to produce anaeration chamber just downstream of the nozzle discharge orifice gap. Inthis sense the word nozzle is used to reference the portion of thebarrel that contains the gap, or the swedging down to the narrowestorifice, thereby recovering the greatest head pressure for discharge.Such nozzle discharge orifice gap can discharge into an aeration chamberwhere aerated foam is produced and is then discharged from the aerationchamber into the atmosphere. U.S. Pat. No. 5,848,752 to Kolacz, inparticular FIG. 3, illustrates this type of foam aeration nozzle. Also,U.S. Pat. No. 4,944,460 to Steingass illustrates this type of aerationfoam nozzle. All things being equal, a separate aeration chamberupstream of the nozzle gap is preferred. However, one of skill in theart would recognize that such is not the only way to create aeratedfoam.

SUMMARY OF MAJOR COMMERCIAL EMBODIMENTS

The Point and Shoot system, at a minimum, includes installing a one ortwo nozzle aerated foam wand system, as a fixed system, preferably every100′ to 240′ around the perimeter of a tank, which should be sufficientto extinguish tank “rim seal fires.”

A good reason for also installing at least one fixed riser proximate alanding, for releasably affixing a portable monitor and nozzle, togetherwith the above one or two nozzle system, would be to provide redundancyand backup foam protection, in case some fixed system units were damageddue to an explosion, and to provide as well a full surface foam“blanket” for “vapor suppression” should a floating roof of the tanksink. Such a fixed monitor riser would have a fire department connectionat the bottom of the tank and a monitor quick disconnect fitting at thetop. During an event, if needed, a firefighter could carry a lightweightaluminum monitor and nozzle to the top of a tank and install the monitoron the riser pipe using the quick disconnect fitting (approximately 2minute installation). From this vantage point, the fire fighter coulddirectly apply foam to needed areas. This maximizes the effectiveness ofthe resources available to the firefighter. The danger and hazard fromlaying fire hoses up a ladder on the side of the tank to implement aportable system are avoided. Williams recommends installing a fixedmonitor riser pipe at locations near landings of the tank. This fixedmonitor riser pipe could also be used to apply foam if necessary to anyexposed areas due to a “cocked” roof or in the event a foam wand headhas been compromised due to an explosion. This elementary semi-fixedsystem minimizes initial capital investment for protection of a tankwithout a fixed roof, at least from a rim seal fire and a sunken roof,while providing a proven system that is easy to operate and to maintain.The equipment eliminates the need to drag multiple hoses up a tank'sladder which impedes firefighters from getting onto or off of the tankquickly.

The Ambush system is a fixed system particularly applicable for fullsurface liquid tank fires and/or rim seal fires, including in largetanks, again as above, preferably for tanks without a fixed roof. TheAmbush system preferably includes three nozzle aerated foam wands, withtwo nozzles that discharge in roughly opposing directions and that canbe oriented with respect to a tank to discharge roughly horizontally.The third nozzle projects in a direction roughly perpendicular to thedischarge axis defined by the first two nozzles. When oriented withrespect to the tank, the third nozzle projects roughly toward the centerof the tank with an appropriate angle of inclination. The third nozzleis preferably structured to land aerated foam at least 100 feet distant.All three nozzles significantly directionally project aerated foam.

The Hollow Point system is a fixed system particularly applicable tohazards and fire in large tanks with a fixed roof, and preferably can beinstalled in and through existing upper tank wall openings. The HollowPoint system is characterized by a conduit ending in a nozzle tip, theconduit having two side discharge ports with associated, largelyinterior “deflectors.” The ports, conduit and nozzle are structured topass through existing tank wall openings and to be oriented with theports discharging in roughly opposing directions, roughly horizontally,and the nozzle tip discharging roughly toward the center. Both thenozzle and ports preferably discharge a substantially focused stream.

The heightened projection capability and foam run capability of eachsystem described above results in the installation and servicing ofsignificantly fewer units per tank than with previous fixed systems. Thenew systems can protect significantly larger tanks with less fixedequipment and in less time. A stream shaper installed in the tip of thenozzles contributes to the heightened projection capability of thenozzles, and together with the development of a properly aerated foam,produces a focused stream and optimized foam run.

Testing

As discussed above, the current accepted fixed system for protectingstorage tanks comprises “foam chambers” (sometimes called “foampourers.”) Fixed foam chambers have limitations, one main limitationbeing their method of applying foam to a seal area. Either because of(1) the degree of aeration produced by the foam chamber and/or (2) aperceived delicacy of the foam bubble and/or the (3) dispersed footprintdischarged, the chamber is structured to only gently “pour” a greatlyexpanded foam down onto a tank's seal. The foam chamber pours; it doesnot throw or project. The foam chamber relies on gravity and the headcreated by the pile of foam to push the foam left and right of the foamchamber. This system severely limits the distance the foam can “run,”left and right of the foam chamber in the seal rim periphery area. Thissystem requires a tank to have a large number of foam chambers spacedaround the circumference, every 40 or 80 feet, depending upon whetherthe “foam dams” of the floating roof are 12″ or 24″. Many tanks are nowgreater than 300 foot diameter. Some are greater than 400 foot diameter.A 400 foot diameter tank with a 12″ foam dam would require about 23traditional foam chambers to protect the periphery. The instantinvention requires only about 6 units to protect the same periphery.

In contrast with the currently accepted fixed systems, Williams hasdeveloped an improved aerated foam nozzle system to discharge a proveneffective foam surprisingly farther, many times farther, in both leftand right directions, than traditional foam chambers. Tests show, below,that the instant system covers a larger area in less time with foam thateffectively extinguishes fire. Further, a rim mounted nozzle has beenalso demonstrated that can run foam to the center of a 400 foot diametertank.

In December of 2010 a “proof of concept” test was run at the WilliamsFire and Hazard Control test facilities. The purpose of the test was tocompare and contrast, by observation, two foam application devicesflowing into a simulated tank “rim seal periphery area,” the onesbetween a tank wall and a floating roof “foam dam.”

The purpose of the test was to determine whether the relative foam flowperformance of the novel Williams projecting foam wand could provide theanticipated benefits compared to a conventional “foam chamber.” Foamfrom both devices was discharged into a simulated floating roof“periphery,” the ones between a tank wall and a floating roof foam dam.For each device the foam traveled through this simulated wall/foam dam“periphery” to reach and extinguish a liquid hydrocarbon pan fire, whichwas simulating a storage tank floating roof “rim seal fire.” Flow ratesand distances were recorded as elements of performance along with thedelivered foam quality, foam expansion ratio and drain time.

The concept being tested was whether the foam applied through a highflow rate projecting foam wand would cover the distance in the seal areamore rapidly and protect a larger segment of a floating roof seal alongthe periphery.

The observed test confirmed the concept. Foam from the projecting foamwand traveled 3 times the distance (120 feet versus 20 feet) in 25% lesstime (74 seconds versus 101 seconds from the chamber.) Both successfullyextinguished a pan fire at their terminus. The novel foam wand appliedfoam more rapidly on the target area than the conventional foam chamber.In addition, the novel foam wand provided a gpm per square footapplication rate 50% greater (0.6 versus 0.4 US gpm per square foot)than the foam chamber. Simulated periphery dimensions were 2 four incheswide and 2 four inches deep.

To summarize the test and the results, a novel aerated foam nozzle wasset up on a mock seal area with a foam dam and flowed alongside atraditional foam chamber. The NFPA recognized maximum distance for atraditional foam chamber to cover is 80′ total, 40′ to the left andright, for a 24″ foam dam. The traditional foam chamber was able tocover this distance in 1 minute 40 seconds. The novel aerated foamnozzle was able to cover an area three times greater in significantlyless time. The aerated foam nozzle covered an area of 240′ (120′ to theleft and right) in 1 minute 14 seconds. It was shown that foam appliedthrough the novel high flow rate wand projecting left and right wouldcover a foam dam seal area more rapidly, travel further per device, andprotect a larger segment of floating roof seal along the periphery.

Further testing of a fixed Hollow Point wand, discussed above, showedthat a roughly 80′×170′ pond of water (13,600 square feet) could becovered in foam with a Hollow Point wand in approximately 1 minute and25 seconds. The furthest corner of the tank from the nozzle was 145′away. That furthest corner received ample foam coverage. The speed, runand authority of the foam was surprising.

Testing of the center nozzle of the Ambush wand, discussed above, alsoindicated a capacity to achieve an approximately 150′ end range of acenter nozzle landing footprint with the mid-point of the landingfootprint at about 130′.

In August 2011 a full Ambush system was tested on a 277 foot diameterempty tank. Six three nozzle wand units were spaced around the peripheryof the tank. The total flow per device was 1500 gpm giving a totalsystem flow of 9,000 GPM. The measured footprint size of the centerpointing nozzle was approximately 60 feet long by 20 feet wide with amid-point range of approximately 90′ away from the nozzle. Byobservation, the total surface of the tank floor was covered with foam.Photographs show testers wading knee deep in foam toward the middle ofthe tank.

SUMMARY OF THE INVENTION

The invention addresses fixed fire fighting systems for large industrialtanks and preferably includes two connected nozzles, each structured toproject aerated foam of between 100 gpm and 900 gpm in substantiallyfocused streams and in roughly opposing directions. The two nozzles eachpreferably have a stream shaper in a tip portion of the nozzle with finsof a longitudinal dimension greater than a radial dimension and whichterminate substantially flush with a nozzle tip solid bore dischargeorifice. The two nozzles preferably are attached proximally downstreamof and in fluid communication with at least one ambient air aerationchamber structured in combination with the two nozzles to produceaerated foam having an expansion of between 2-to-1 to 8-to-1. A thirdnozzle of the fixed system is preferably structured to discharge between200 gpm and 900 gpm in a direction of within 30° of a perpendicular tothe discharge axis defined by the two nozzles discharging in the roughlyopposing directions.

The fixed system preferably includes at least one riser forcommunicating water and foam concentrate, attached to and in fluidcommunication with the two nozzles, and possibly the third nozzle. Afirst riser can be attached to two connected nozzles and a second risercan be attached to a third nozzle, or alternately all nozzles can beattached to a first riser. The second riser can be located proximate tothe first riser, or not. A second ambient air aeration chamber may beassociated with the third nozzle to produce aerated foam. Preferably thesystem includes a valve attached upstream of a second ambient airaeration chamber.

The invention addresses fixed fire fighting systems for large industrialtanks also preferably including at least one first aerated foamprojecting nozzle, in fluid communication with and located proximate toand downstream of an ambient air aeration chamber. The nozzle andaeration chamber are preferably structured together for producing foamwith an expansion of between 2-to-1 to 8-to-1. The nozzle preferably hasa stream shaper in its tip and is affixed to the tank so as to dischargea substantially focused stream roughly horizontally along an upper innertank wall portion. A centrally directed nozzle is preferably alsoaffixed proximate the top tank wall, located and structured to dischargeroughly toward the center of the tank.

The centrally directed nozzle may be in fluid communication with anaeration chamber located proximate to and upstream of the centrallydirected nozzle. The centrally directed nozzle may have a stream shaperin its tip and be structured to produce foam in combination with theaeration chamber having an expansion of 2-to-1 to 8-to-1.

Preferably there are two aerated foam projecting nozzles affixed to thetank so as to discharge a substantially focused stream roughlyhorizontally and in roughly opposing directions. Preferably the aeratedfoam projecting nozzle or nozzles are structured to discharge between100 gpm and 900 gpm. Preferably the aerated foam projecting nozzle ornozzles are attached to the tank and to a riser attached proximate thetank.

The invention also addresses fixed systems for fighting fire in largeindustrial tanks with a fixed roof, preferably including a first ambientair aeration chamber located upstream of, and fluid communication with,and proximate to, a fire fighting nozzle. The first ambient air aerationchamber is preferably structured to produce aerated foam. The firefighting nozzle preferably includes at least one stream shaper locatedin a tip portion of the nozzle. The stream shaper preferably has finswith a longitudinal dimension greater than a radial dimension, and thefins preferably terminate substantially flush with a solid bore tipdischarge orifice. At least two discharge ports are preferably locatedin a fluid conduit between the aeration chamber and the nozzle tip witheach discharge port having a deflector portion located in the conduitproximate the port for deflecting fluid passing through the conduit outthe port. A stream straightener is also preferably located upstream ofand proximate the discharge ports. Stream straighteners (for locatingupstream of a discharge orifice) are known in the art and can bepurchased, for instance, from Elkhart Brass.

The invention also includes a fixed aerated foam fire fighting systemfor a tank with a fixed roof including a first ambient air aerationchamber located upstream of, and fluid communication with, and proximateto, a forcefully projecting fire fighting nozzle, forcefully projectingaerated foam in a substantially focused stream, with the aerationchamber structured to produce aerated foam. The invention includes atleast two discharge ports in a fluid conduit between the aerationchamber and a nozzle tip, each port having a deflector portion locatedin the conduit proximate to the port to deflect fluid to the port. Theinvention preferably includes a stream straightener located upstream ofand proximate the discharge ports. (Such mid-stream stream straightenersare known in the art.)

Preferably the ambient air aeration chamber is structured to produceaerated foam roughly horizontally with an expansion of between 2-to-1 to8-to-1, and more preferably with an expansion of between 3-to-1 to5-to-1.

Preferably the at least two discharge ports are structured to dischargeaerated foam roughly horizontally in roughly opposing directions.Preferably the system includes an at least four inch riser structuredfor communicating fire fighting fluid outside of the tank wall and influid communication with the aeration chamber. Preferably a vapormembrane is located between the riser and the aeration chamber.

The invention also includes an aeration chamber structured to produceaerated foam with an expansion of between 2-to-1 to 8-to-1, and a fluidconduit attached between the aeration chamber and a nozzle tip. Thenozzle is structured to forcefully project between 200 gpm and 1000 gpm,at 100 psi, of aerated foam with an expansion of between 2-to-1 to8-to-1, in a substantially focused stream. The conduit includes a pairof substantially opposing discharge ports with interior deflectorsurfaces, the surfaces structured to deflect a portion of fire fightingfluid passing through the conduit toward the ports.

The invention also includes a fixed system fire fighting method for anindustrial tank, including projecting aerated foam substantiallyhorizontally along inner tank wall portions in an substantially focusedstream from at least one aerated foam projecting nozzle. The methodincludes producing from the nozzle aerated foam having an expansion ofbetween 2-to-1 to 8-to-1 and forcefully projecting foam from a centerdirected nozzle roughly toward the center of the tank, the centerdirected nozzle affixed proximate an inner tank wall portion. Preferablythe invention includes projecting aerated foam substantiallyhorizontally along inner tank wall portions from a first and secondaerated foam projecting nozzle, roughly horizontally and in generallyopposing directions.

The invention also includes a method for extinguishing fire in a fixedroof large industrial tank, including affixing a conduit, having anaerated foam, forcefully projecting nozzle at its distal end, through anopening at a top portion of a large industrial tank wall. The inventionpreferably includes forcefully projecting aerated foam, having anexpansion of between 2-to-1 to 8-to-1, radially toward the center of thetank in a substantially focused stream and projecting aerated foamthrough two discharge ports on the side of the conduit, roughlyhorizontally and in roughly opposing directions, along interior sidewall portions of the tank.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when thefollowing detailed description of the preferred embodiments areconsidered in conjunction with the following drawings, in which:

FIG. 1 illustrates an embodiment of a fixed system having two aeratedfoam projecting nozzles discharging foam in opposing directions, roughlyhorizontally, along a top portion of a tank wall and having a thirdcenter projecting nozzle connected thereto, with the projecting nozzleand the pair of aerated foam projecting nozzles each having their ownambient air aeration chamber proximately upstream.

FIG. 2 is a cut-away view of the embodiment of FIG. 1.

FIG. 3A indicates the embodiment of FIG. 1 including the attachment ofthe three nozzles to a single riser located proximate the outside tankwall of a tank.

FIGS. 3B and 3C illustrate alternate embodiments for a fixed system withthe aerated foam projecting nozzles projecting horizontally along thetank wall and including the center pointing nozzle. FIGS. 3B and 3Cillustrate that the center pointing nozzle can be attached to its ownriser, independently of the riser for the pair of aerated foamprojecting nozzles projecting horizontally along the inner tank wall.

FIGS. 4A-4D are drawings illustrating the embodiment of FIG. 3A indetail.

FIGS. 5A-5F are drawings of the “wand head” of FIG. 3A in detail, thewand head including nozzle wand head with a center pointing nozzle and apair of left/right foam projecting inner wall nozzles.

FIG. 6 is relevant because of FIG. 3B. FIG. 3B presents an embodimentwhere the riser for the center pointing nozzle is separate from theriser for the two left/right directed nozzles. Hence, the centerpointing nozzle can actually be located independently and separatelyfrom the left/right directed nozzles, using its own riser. Preferably ariser includes a riser top portion, a riser extension pipe and a riserinlet pipe, as illustrated in FIG. 6.

FIG. 7 illustrates a foot rest kit to help support an independent riser,also attached by brackets to a tank wall.

FIGS. 8A-8G illustrates with drawings the embodiment of FIG. 6 forestablishing a fixed riser proximate a tank wall, useful for attaching acenter pointing nozzle.

FIG. 9 is a table correlating preferred flow rates for the left rightpointing nozzle and the center pointing nozzle, referred to as “upper,”to tank diameters.

FIG. 10 illustrates planning for an arrangement of nozzles of the Ambushsystem, including the three fixed nozzle type, given a tank size.

FIG. 11 illustrates a proposed placement of three nozzle fixed wands tocover a fire in a 300 foot diameter tank.

FIG. 12 illustrates staging three nozzle wands around a 405 footdiameter tank, including gpms.

FIG. 13 illustrates staging three nozzle fixed wands around a 277 footdiameter tank, including flow per device, effective ranges and footprintsize.

FIG. 14 illustrates a fixed nozzle wand for fitting into an existingopening of a tank with a fixed roof.

FIG. 15 is a partial cutaway of the nozzle of FIG. 14.

FIG. 16 is a side view of the nozzle of FIG. 14, showing the fixednozzle wand installed through a tank wall.

FIG. 17 shows the embodiment of FIG. 14 together with a riser to form afull wand.

FIG. 18 shows the embodiment of FIG. 14 together with the riser to forma full wand attached to a tank wall.

FIGS. 19A-19C show the embodiment of FIG. 14 together with the riser,attached to a tank wall and with an indication of further sourcing ofwater and foam concentrate.

FIG. 20 illustrates the number of fixed nozzle systems with dual sideports required for full surface protection of a fixed roof tank, by tankdiameter.

The drawings are primarily illustrative. It would be understood thatstructure may have been simplified and details omitted in order toconvey certain aspects of the invention. Scale may be sacrificed toclarity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a preferred embodiment of a wand head WH for a fixedfire fighting system for a large industrial tank. The wand head WH isindicated as installed proximate to the tank wall portion TW, in factutilizing support panel SP for extra support. The nozzles AFPN and CPNof the wand head are located with respect of the tank to discharge justover the tank wall. The embodiment of FIG. 1 includes center pointingnozzle CPN and a pair of aerating foam projecting nozzles AFPN. Theaerating foam projecting nozzles discharge substantially horizontallyand in roughly opposing directions along an upper interior edge of thetank wall TW. The aerated foam projecting nozzles are shown with a tipportion TP and a stream shaper SS located in the tip having fins FN thatterminate substantially flush with the discharge opening DO of the tip.Riser RS passes through the wind girder WG and furnishes water and foamconcentrate to the embodiment of three nozzles. Each nozzle is shownwith its own ambient air aeration chamber AAAC locating proximate to thenozzle and just upstream of the nozzle.

FIG. 2 is a partial cutaway of the embodiment of FIG. 1. The ambient airaeration chambers can be shown to be of a tubular jets type having atubular jets TJ within ports for drawing in air in a fashion known inthe art. The embodiment of FIG. 1 is further illustrated in FIG. 3showing a full riser RS coming from proximate the ground and rising toproximate the top of the tank wall TW. The riser passes through the windgirder WG.

FIGS. 3B-1 and 3B-2 illustrates an alternate embodiment of the instantfixed system invention illustrated in FIG. 3A. In FIG. 3B the centerpointing nozzle CPN, although nominally attached to the conduit of thepair of aerated foam projecting nozzles AFPN, has not only its separateambient air aeration chamber AAAC2 (from AAAC1) but its separate riserRS2 (from RS1.) Given the configuration of FIG. 3B, it is clear that thecenter pointing nozzle can actually be physically separated from thewand of the pair of aerated foam projecting nozzles. Each can have theirown aeration chamber and each can have their own riser.

It becomes further apparent that riser RS2 not only need not be locatednext to riser one RS1, but the nozzle attached to the second riser couldactually be any effective fire fighting nozzle for discharging foam tocover center portions of the tank. It may, but need not have, aproximate ambient air aeration chamber AAAC2. It could be a nozzle ofthe sort that relies upon aeration by virtue of substantial flight ofthe air.

FIGS. 4A-4D offer a drawing sheet showing particulars of the wand headof the embodiment of FIG. 1. FIG. 4C illustrates by dashed lines theroughly horizontal direction and roughly opposing directions of the pairof aerated foam projecting nozzles.

FIGS. 5A-5F show further details of the wand head of the embodiment ofFIG. 1 including drawing cutaways showing the tubular jet TJ in theaeration chamber AAAC, the stream shaper SS and the fins FN therein.

FIG. 6 illustrates three sections of a potentially free standing riserthat might be used to separately locate a center pointing nozzle of anyappropriate size and style. These riser portions, including a riser topportion RTP, a riser extension pipe REP and riser inlet pipe RIP, areintended to be joined together and provide a free standing riser forattaching (most likely) a center pointing nozzle. The center pointingnozzle could be fixedly attached, and as discussed previously, need notnecessarily include an ambient air aeration chamber. FIG. 7 illustratesa riser foot rest RFR and a bracket BR both useful for securing a riserRS proximate a tank wall. FIGS. 8A-8G illustrates in further detail ariser RS and method and apparatus for securing a riser proximate andadjacent a tank wall, including brackets BR and riser footrest RFR.

FIG. 9 illustrates figuring a three nozzle fixed wand configuration intoa system for tank sizes from 150 foot diameter to a 500 foot diameter. Aproposed optimum flow both for the left and right pointing aeratingprojecting nozzles and for upper and center pointing nozzles isindicated.

FIG. 10 illustrates calculations that affect the type and number offixed three nozzle wands required for a tank surface. FIG. 10 indicatesthat in the annular area, supplied with foam by the aerated foamprotecting nozzles, an application rate of 0.10 gpm per square foot isrecommended. For the open surface area of the middle of the tank, anapplication rate of at least 0.16 gpm per square foot is recommended.

FIG. 11 represents calculations for a fixed system of the instantinvention for a 300 foot diameter tank. The tank is shown configuredwith seven fixed systems discharging left, right, and toward the center.Application rate densities are indicated. Total gpm for all devices isindicated as well as the gpm per three nozzle wand. A gpm against thewall indicated in FIG. 11 comes from a port in the conduit thatdischarges up to 150 gpm down under any wand as a safeguard.

FIG. 12 illustrates calculations for a 405 foot diameter tank where tenthree nozzle wands are proposed each wand providing 1,300 gpm totalagainst the inner wall and 600 gpm toward the center. FIG. 12 indicatesa design of a fixed three nozzle aerated foam wand system forextinguishing a full surface liquid tank fire in a 405 foot diametertank. Ten dispersing units are prescribed. Each unit is assumed to havethree nozzles, one dispersing to the left, one to the right and onetoward the center. All three nozzles disperse 600 gpm. In addition 100gpm is dispersed downward against the wall. (This fourth direction maynot be needed, or may be optional). The landing footprints for the tennozzles discharging toward the center of the tank are predicted toproject a footprint to land approximately 150 feet away from the tankwall. The foam should easily run an additional 55 feet or so toward thecenter, as well as return back toward the wall 30 feet or more to meetfoam from the nozzles discharging left and right expanding toward thecenter of the tank from the walls. The drawing FIG. 12 in additionindicates a fallout region from the discharge path of the nozzlesdischarging toward the center of the tank. The fallout region suppliesfoam into mid-radial annular areas of the tank. The drawing indicates acapacity to blanket a 400 foot diameter tank with foam using ten fixedunits.

An attached spreadsheet shows how the three nozzle fixed system can planand provide a fixed system full surface fire protection for tank sizesfrom 100 foot diameter to 500 foot diameter.

Total Flow Flow Required Required Distance to Achieve From Actual FlowNumber Desired Actual Surface Between Desired Each from each Tank ofApplication Application Area of Tank Devices Application Device ActualTotal Device Size Devices Density Density Tank Circumference (<180′)Density (<Actual) Flow (GPM) 100 2 0.12 0.17 7850 314 157 942 471 1300650 110 2 0.12 0.14 9499 345 173 1140 570 1300 650 120 3 0.12 0.17 11304377 126 1356 452 1950 650 130 3 0.12 0.15 13267 408 136 1592 531 1950650 140 3 0.12 0.13 15386 440 147 1846 615 1950 650 150 4 0.12 0.1517663 471 118 2120 530 2600 650 160 4 0.12 0.13 20096 502 126 2412 6032600 650 170 3 0.12 0.15 22687 534 178 2722 907 3300 1100 180 4 0.120.17 25434 565 141 3052 763 4400 1100 190 4 0.12 0.16 28339 597 149 3401850 4400 1100 200 4 0.12 0.14 31400 628 157 3768 942 4400 1100 210 40.12 0.13 34619 659 165 4154 1039 4400 1100 220 5 0.12 0.14 37994 691138 4559 912 5500 1100 230 5 0.12 0.13 41527 722 144 4983 997 5500 1100240 5 0.13 0.17 45216 754 151 5878 1176 7500 1500 250 5 0.13 0.15 49063785 157 6378 1276 7500 1500 260 5 0.13 0.14 53066 816 163 6899 1380 75001500 270 5 0.13 0.13 57227 848 170 7439 1488 7500 1500 280 6 0.13 0.1561544 879 147 8001 1333 9000 1500 290 6 0.13 0.14 66019 911 152 85821430 9000 1500 300 7 0.13 0.15 70650 942 135 9185 1312 10500 1500 310 80.13 0.16 75439 973 122 9807 1226 12000 1500 320 6 0.14 0.14 80384 1005167 11254 1876 11400 1900 330 7 0.14 0.16 85487 1036 148 11968 171013300 1900 340 7 0.14 0.15 90746 1068 153 12704 1815 13300 1900 350 80.14 0.16 96163 1099 137 13463 1683 15200 1900 360 9 0.15 0.17 1017361130 126 15260 1696 17100 1900 370 8 0.15 0.16 107467 1162 145 161202015 16800 2100 380 9 0.15 0.17 113354 1193 133 17003 1889 18900 2100390 9 0.15 0.16 119399 1225 136 17910 1990 18900 2100 400 10 0.15 0.17125600 1256 126 18840 1884 21000 2100 410 10 0.15 0.16 131959 1287 12919794 1979 21000 2100 420 9 0.16 0.18 138474 1319 147 22156 2462 243002700 430 10 0.16 0.19 145147 1350 135 23223 2322 27000 2700 440 10 0.160.18 151976 1382 138 24316 2432 27000 2700 450 11 0.16 0.19 158963 1413128 25434 2312 29700 2700 460 12 0.16 0.20 166106 1444 120 26577 221532400 2700 470 13 0.16 0.20 173407 1476 114 27745 2134 35100 2700 480 130.16 0.19 180864 1507 116 28938 2226 35100 2700 490 14 0.16 0.20 1884791539 110 30157 2154 37800 2700 500 15 0.16 0.21 196250 1570 105 314002093 40500 2700 Ambush System 3″-5″ Flow Breakdown Open Surface AnnularArea Foam (GPM) Surface Surface Application Total Upper Surface TotalApplication Blanket Left Right Upper Wall Diameter Area Density Flow(GPM) Area Flow Density (minutes) 300 300 0 50 0 0 0.00 0 7850 1300 0.173.7 300 300 0 50 0 0 0.00 0 9499 1300 0.14 4.5 300 300 0 50 0 0 0.00 011304 1950 0.17 3.6 300 300 0 50 0 0 0.00 0 13267 1950 0.15 4.2 300 3000 50 0 0 0.00 0 15386 1950 0.13 4.9 300 300 0 50 0 0 0.00 0 17663 26000.15 4.2 300 300 0 50 0 0 0.00 0 20096 2600 0.13 4.8 400 400 200 100 1079 7.64 600 22608 2700 0.12 4.3 400 400 200 100 20 314 2.55 800 251203600 0.14 3.6 400 400 200 100 30 707 1.13 800 27632 3600 0.13 4.0 400400 200 100 40 1256 0.64 800 30144 3600 0.12 4.4 400 400 200 100 50 19630.41 800 32656 3600 0.11 4.9 400 400 200 100 60 2826 0.35 1000 351684500 0.13 4.3 400 400 200 100 70 3847 0.26 1000 37680 4500 0.12 4.7 500500 400 100 80 5024 0.40 2000 40192 5500 0.14 3.7 500 500 400 100 906359 0.31 2000 42704 5500 0.13 4.1 500 500 400 100 100 7850 0.25 200045216 5500 0.12 4.4 500 500 400 100 110 9499 0.21 2000 47728 5500 0.124.7 500 500 400 100 120 11304 0.21 2400 50240 6600 0.13 4.2 500 500 400100 130 13267 0.18 2400 52752 6600 0.13 4.5 500 500 400 100 140 153860.18 2800 55264 7700 0.14 4.2 500 500 400 100 150 17663 0.18 3200 577768800 0.15 3.9 600 600 600 100 160 20096 0.18 3600 60288 7800 0.13 4.4600 600 600 100 170 22687 0.19 4200 62800 9100 0.14 4.0 600 600 600 100180 25434 0.17 4200 65312 9100 0.14 4.2 600 600 600 100 190 28339 0.174800 67824 10400 0.15 3.9 600 600 600 100 200 31400 0.17 5400 7033611700 0.17 3.7 600 600 800 100 210 34619 0.18 6400 72848 10400 0.14 4.0600 600 800 100 220 37994 0.19 7200 75360 11700 0.16 3.7 600 600 800 100230 41527 0.17 7200 77872 11700 0.15 3.9 600 600 800 100 240 45216 0.188000 80384 13000 0.16 3.7 600 600 800 100 250 49063 0.16 8000 8289613000 0.16 3.9 800 800 1000 100 260 53066 0.17 9000 85408 15300 0.18 3.5800 800 1000 100 270 57227 0.17 10000 87920 17000 0.19 3.3 800 800 1000100 280 61544 0.16 10000 90432 17000 0.19 3.5 800 800 1000 100 290 660190.17 11000 92944 18700 0.20 3.3 800 800 1000 100 300 70650 0.17 1200095456 20400 0.21 3.2 800 800 1000 100 310 75439 0.17 13000 97968 221000.23 3.1 800 800 1000 100 320 80384 0.16 13000 100480 22100 0.22 3.2 800800 1000 100 330 85487 0.16 14000 102992 23800 0.23 3.1 800 800 1000 100340 90746 0.17 15000 105504 25500 0.24 3.0 Open Surface Seal Area ofMeet Acceptable? Equivalent Seal Area 1% foam 3% foam 0.16 Actual >=Open Area Time flow flow Requirement Requirement Surface 615 1.3 7152145 0 YES 0 678 1.4 715 2145 0 YES 0 741 1.0 1073 3218 0 YES 0 804 1.11073 3218 0 YES 0 867 1.2 1073 3218 0 YES 0 929 1.0 1430 4290 0 YES 0992 1.0 1430 4290 0 YES 0 1055 0.9 2145 6435 3750 YES 69 1118 0.7 28608580 5000 YES 80 1181 0.7 2860 8580 5000 YES 80 1243 0.8 2860 8580 5000YES 80 1306 0.8 2860 8580 5000 YES 80 1369 0.7 3575 10725 6250 YES 891432 0.7 3575 10725 6250 YES 89 1495 0.5 4875 14625 12500 YES 126 15570.6 4875 14625 12500 YES 126 1620 0.6 4875 14625 12500 YES 126 1683 0.64875 14625 12500 YES 126 1746 0.5 5850 17550 15000 YES 138 1809 0.5 585017550 15000 YES 138 1871 0.5 6825 20475 17500 YES 149 1934 0.4 780023400 20000 YES 160 1997 0.5 7410 22230 22500 YES 169 2060 0.4 864525935 26250 YES 183 2123 0.4 8645 25935 26250 YES 183 2185 0.4 988029640 30000 YES 195 2248 0.3 11115 33345 33750 YES 207 2311 0.4 1092032760 40000 YES 226 2374 0.3 12285 36855 45000 YES 239 2437 0.3 1228536855 45000 YES 239 2499 0.3 13650 40950 50000 YES 252 2562 0.3 1365040950 50000 YES 252 2625 0.3 15795 47385 56250 YES 268 2688 0.3 1755052650 62500 YES 282 2751 0.3 17550 52650 62500 YES 282 2813 0.2 1930557915 68750 YES 296 2876 0.2 21060 63180 75000 YES 309 2939 0.2 2281568445 81250 YES 322 3002 0.2 22815 68445 81250 YES 322 3065 0.2 2457073710 87500 YES 334 3127 0.2 26325 78975 93750 YES 346

FIG. 13 illustrates configuring 6 three nozzle fixed system wands tocover a 277 foot diameter tank. Each device would flow 1500 gpm giving atotal system flow of 9000 gpm.

FIG. 14 illustrates a riser RS and nozzle system appropriate forretro-fitting a tank with a fixed roof. The nozzle is designed such thatit can be inserted into an opening near the top of the side of the tankwall. A center pointing nozzle CPN is provided with a tip TP. A pair ofports P are provided on each side of the nozzle, each port having adeflector DF which deflects foam from the conduit out the ports. Anambient air aeration chamber AAAC is provided on top of a riser RS.

FIG. 15 is a partial cross section of the embodiment of FIG. 14. It canbe seen that a vapor seal VS is present between two flanges just abovethe jet nozzle TJ of the ambient air aeration chamber AAAC. The vaporseal is ruptured by a water stream when activating of the system. Abetter view of the deflectors DF proximate the ports P is given with thecutaway view, together with the location of the stream shaper SS and itsfins FN in the tip TP of the center pointing nozzle CPN.

FIG. 16 affords a side view of the embodiment of FIG. 15, showing thenozzle affixed through a flanged opening FO of the tank wall TW.

FIG. 17 affords a full wand view of the embodiment of FIG. 14 with theriser RS attached to the wand head and the wand carrying the centerpointing nozzle CPN.

FIG. 18 illustrates again the nozzle embodiment of FIG. 14 installedthrough an opening FO of a tank wall TW of tank T. FIG. 18 alsoillustrates the riser RS bringing water foam concentrate from proximatethe ground up to the nozzle located proximally a top portion of the tankwall.

FIGS. 19A-19C illustrates a further installation of the nozzleembodiment of FIG. 14 in a tank wall TW under a fixed roof FR andincluding riser RS.

FIG. 20 illustrates a computation of the required number of embodimentsof a nozzle for a fixed roof in accordance with the embodiment of FIG.14, as per tank diameter. Each nozzle as per the embodiment of FIG. 14is designed to discharge a 1000 gpm total.

The foregoing description of preferred embodiments of the invention ispresented for purposes of illustration and description, and is notintended to be exhaustive or to limit the invention to the precise formor embodiment disclosed. The description was selected to best explainthe principles of the invention and their practical application toenable others skilled in the art to best utilize the invention invarious embodiments. Various modifications as are best suited to theparticular use are contemplated. It is intended that the scope of theinvention is not to be limited by the specification, but to be definedby the claims set forth below. Since the foregoing disclosure anddescription of the invention are illustrative and explanatory thereof,various changes in the size, shape, and materials, as well as in thedetails of the illustrated device may be made without departing from thespirit of the invention. The invention is claimed using terminology thatdepends upon a historic presumption that recitation of a single elementcovers one or more, and recitation of two elements covers two or more,and the like. Also, the drawings and illustration herein have notnecessarily been produced to scale.

What is claimed is:
 1. An aerated foam fire fighting apparatusstructured for attachment to a tank with a fixed roof, comprising: anambient air aeration chamber located upstream of, in fluid communicationwith, and proximate to, a nozzle, the ambient air aeration chamberstructured to produce aerated foam; and the nozzle comprising: at leastone stream shaper located in a tip portion of the nozzle, the at leastone stream shaper having fins with a longitudinal dimension greater thana radial dimension, the fins terminating flush with an outermost end ofthe nozzle, wherein the nozzle is affixed to the tank so that theoutermost end of the nozzle is positioned to discharge the aerated foamtoward a center of the tank; and at least two discharge ports located ina fluid conduit between the ambient air aeration chamber and theoutermost end of the nozzle, each discharge port of the at least twodischarge ports having a deflector portion located in the fluid conduitproximate the respective discharge port, wherein the at least twodischarge ports are positioned to discharge the aerated foam in opposingdirections along an inner tank wall, wherein a diameter at the outermostend of the nozzle is smaller than a diameter at the at least twodischarge ports.
 2. The aerated foam fire fighting apparatus structuredfor attachment to the tank with a fixed roof of claim 1, including: thenozzle structured with the ambient air aeration chamber to projectaerated foam in a substantially focused stream.
 3. The aerated foam firefighting apparatus of claim 1 or 2 wherein the ambient air aerationchamber is structured to produce aerated foam with an expansion ratio ofbetween 2-to-1 and 8-to-1.
 4. The aerated foam fire fighting apparatusof claim 3 including: the nozzle structured to forcefully projectbetween 200 gallons per minute (gpm) and 1000 gpm, at 100 pound persquare inch (psi), of aerated foam; and the at least two discharge portsincluding: a pair of substantially opposing discharge ports upstream ofthe outermost end of the nozzle, with interior deflector surfacesstructured to deflect a portion of fire fighting fluid passing throughthe conduit toward the at least two discharge ports.
 5. The aerated foamfire fighting apparatus of claim 1 or 2 wherein the ambient air aerationchamber is structured to produce aerated foam with an expansion ratio ofbetween 3-to-1 and 5-to-1.
 6. The aerated foam fire fighting apparatusof claim 5 including: the nozzle structured to project between 200gallons per minute (gpm) and 1000 gpm, at 100 pound per square inch(psi), of aerated foam; and the at least two discharge ports including;a pair of substantially opposing discharge ports upstream of theoutermost end of the nozzle, with interior deflector surfaces structuredto deflect a portion of fire fighting fluid passing through the conduittoward the at least two discharge ports.
 7. The aerated foam firefighting apparatus of claim 1 or 2 including an at least 4 inch riserstructured for communicating fire fighting fluid outside of an outertank wall and in fluid communication with the aeration air aerationchamber.
 8. The aerated foam fire fighting apparatus of claim 7including a vapor membrane located between the riser and the aerationair aeration chamber.
 9. The aerated foam fire fighting apparatus ofclaim 1 further comprising a conduit bend between the ambient airaeration chamber and the nozzle.
 10. The aerated foam fire fightingapparatus of claim 9 wherein the conduit bend comprises a 90° bend. 11.The aerated foam fire fighting apparatus of claim 9 wherein the at leasttwo discharge ports consist of two discharge ports; and wherein theaerated foam, generated from the ambient air aeration chamber, exitsonly from the outermost end of the nozzle and the two discharge ports.12. The aerated foam fire fighting apparatus of claim 9 furthercomprising a vapor seal between the conduit bend and the ambient airaeration chamber, wherein the vapor seal is ruptured by a water stream.13. The aerated foam fire fighting apparatus of claim 1 wherein thenozzle consists of two discharge ports.
 14. The aerated foam firefighting apparatus of claim 1 further comprising a ring configured toconnect the nozzle to a flanged opening of the tank.
 15. The aeratedfoam fire fighting apparatus of claim 1, wherein the tip portion of thenozzle is cylindrical in shape; and wherein the nozzle includes atapered swedge down portion between the tip portion of the nozzle andthe at least two discharge ports.
 16. The aerated foam fire fightingapparatus of claim 15, wherein the tapered swedge down portion does notinclude the at least one stream shaper.
 17. The aerated foam firefighting apparatus of claim 16, wherein the at least two discharge portsare formed in the fluid conduit that is cylindrical in shape.